The production of coated refractory fibers is known and is taught, for example, in U.S. Pat. No. 3,428,519, issued Feb. 18, 1969 to Carl M. Zvanut. U.S. Pat. No. 3,565,683, issued Feb. 23, 1971 to Charles R. Morelock shows the coating of quartz and silica fibers with carbon which is electrically conductive and which is overcoated with a boro-carbon conductive coating. Such coated fibers as are discussed in the abovementioned patents have not been formulated into either woven cloths or non-woven cloths. And, if one were to attempt to do this it is highly unlikely that the coating would remain intact and undamaged.
U.S. Pat. No. 3,676,293, issued July 11, 1972 to Bernard A. Gruber, discloses a fabric of silicon carbide fibers coated with pyrolyzed carbon from a resin. The end product is a refractory. The silicon carbide is not electrically insulating but is instead a semiconductor.
U.S. Pat. No. 3,969,124, issued July 13, 1976 to Wilfred S. Stewart, discloses the formation of high strength shaped carbonaceous articles by shaping and curing particles of carbon, graphite and mixtures thereof with a resin binder and thereafter pyrolyzing the shaped article. The bulk density of the article can be increased and the porosity reduced by vapor deposition of graphite in its pores. The article may be reinforced with fibers and whiskers of various refractory materials including aluminum oxide. Such shaped articles are not, however, in the nature of a flexible cloth.
U.S. Pat. No. 4,321,154, issued Mar. 23, 1982 to Francois Ledru discloses a thermal insulating material comprising insulating mineral fibers bonded in a matrix which is formed in part by pyrolytic carbon. The resulting material has very low heat conductivity. There is no teaching of the material being electrically conducting.
U.S. Pat. No. 4,407,969 discloses a flexible thermally insulative refractory composition which is resistant to attack by molten material. It may contain inorganic fiber and any of various polymers. The composition is normally insulative.
U.S. Pat. No. 3,281,261 discloses coating a fabric such as rayon, cotton or polyacrylate with a refractory such as alumina and then carbonizing to provide a ceramic fabric having considerable strength.
The prior art does not teach or suggest a flexible electrically conducting cloth having an appropriate sheet resistance for use as a heating element, as an antenna, as an electromagnetic reflector, or as electromagnetic field shielding.